Breast imaging using light and sound.

Breast cancer is one of the most common forms of female cancers worldwide. Current imaging modalities suffer from some major limitations. This observational diagnostic study investigates the feasibility of photoacoustic mammography in breast cancer imaging. Within a period of two years, up to 100 patients from the Centre of Mammacare of the Medisch Spectrum in Twente will be included in the study based on the grade of suspiciousness of their lesions. Patients that agree on cooperation and sign an informed consent form will undergo a 45 minutes lasting non-invasive imaging procedure of the breast lesion. The photoacoustic images will be compared with the results of conventional imaging (X-ray mammography, ultrasonography and, if applicable, Magnetic Resonance Imaging) and if available with histopathology results.

The main objectives of this study are:

1. To optimize the imaging and analyis methods for the visualization of malignancies;

2. To find the photaocoustic markers that are indicative for the presence of a malignancy;

3. To guide the developments of the further generations of the photoacoustic mammoscope.

Breast cancer is one of the most common forms of female cancer worldwide. There are major limitations to the current imaging techniques that are used for diagnosing breast cancer. There is no single technique that combines an excellent sensitivity with a good specificity, an appropriate resolution and a high imaging contrast and that can be used in the complete adult female population. In the last years, researchers from the University of Twente have made progress in the development of a new technique for breast cancer imaging: photoacoustic mammography. This technique combines the high contrast of optical imaging with the good resolution of ultrasound. Besides, the contrast is based on functional processes instead of on morphological tissue changes. The clinical feasibility of photoacoustic mammography has been tested with realistic breast phantoms and in a pilot study. We are now at the stage that more clinical data is needed in order to guide the developments of this technique and to find photoacoustic markers that are indicative for malignancy.

The photoacoustic images will be analysed after each measurement. Adaptations to the measurement protocol or slight adaptations with respect to safety and comfort can be applied after each measurement. After each phase, the study will be paused for a few weeks to optimise the imaging and analysis methods.

No interventions.

Measurements:

Patients who come to the centre for mammacare with a suspicious breast lesion and who follow the inclusion criteria of the current phase, will be asked for cooperation to the study in between the conventional diagnosis and the ultrasound guided biopsy. If the patient agrees on cooperation and signs an informed consent form, her breast will be imaged with the photoacoustic mammoscope. During the measurement the woman has to lie on the bed in a prone position with her breast pendant through the whole in the bed. The breast will be slightly compressed between a window for laser light illumination and an ultrasound detector array. After careful positioning and defining the region of interest, a scan of about 30 minutes will be made. During the scan the patient and all bystanders wear special laser safety goggles. The energy and beam surface are set such that the total fluence is always below the MPE (maximal permissible exposure) safety guidelines.